THE PROPOSED STUDY WILL INVESTIGATE THE UTILITY OF A LAYERED LASER DEFENSE SYSTEM (LLDS) DESIGNED TO ELIMINATE U.S. BOOSTERS AND/OR REENTRY VEHICLE SYSTEMS. THE PRINCIPAL OBJECTIVE IS TO IDENTIFY AND EVALUATE ACTIVE COUNTERMEASURES DESIGNED TO DEFEAT ONE OR MORE LAYERS OF THE LLDS. TASKS TO BE ACCOMPLISHED INCLUDE: (1) THREAT DEFINITION; (2) MISSILE BASELINE VULERABILITY ASSESSMENT; (3) BASELINE SYSTEM PERFORMANCE MODELING; (4) COUNTERMEASURE DEFINITION; (5) COUNTERMEASURE EVALUATION; AND (6) TECHNOLOGY DEVELOPMENT RE QUIREMENTS SPECIFICATION. THE ANTICIPATED RESULTS OF THIS STUDY WILL INCLUDE: (1) AN ASSESSEMENT OF THE SERIOUSNESS OF THE DEFINED THREAT; (2) THE IDENTIFICATION OF APPROPRIATE COUNTERMEASURES TO DEFEAT THE THREAT; AD (3) A SPECIFICATION OF THE TECHNOLOGY DEVELOP MENT REQUIRED TO RESOLVE CRITICAL DEPLOYMENT ISSUES.